Amiga: bound BufferQueueChar; move CloseWindow out of Forbid()

Make the BufferQueueChar macro bounds-check KbdBuffered against
KBDBUFFER internally so the RAWKEY and NEWSIZE 'R'-64 paths can
no longer push past the 10-byte queue; widen KbdBuffered to int
so the counter cannot wrap silently in the queue-scan loops.

In amii_cleanup move kill_nhwindows()/DeleteMsgPort() outside
the Forbid()/Permit() pair: CloseWindow can wait on layers.library
semaphores on OS 3.x and that is unsafe under Forbid.  Keep only
the IDCMP-flush loop inside.

sys/amiga/amiwind.c

@@ -19,7 +19,8 @@ static struct Message *GetFMsg(struct MsgPort *);
 static int BufferGetchar(void);
 void ProcessMessage(struct IntuiMessage *message);
 
-#define BufferQueueChar(ch) (KbdBuffer[KbdBuffered++] = (ch))
+#define BufferQueueChar(ch) \
+    do { if (KbdBuffered < KBDBUFFER) KbdBuffer[KbdBuffered++] = (ch); } while (0)
 
 struct Device *ConsoleDevice = NULL;
 
@@ -51,7 +52,7 @@ struct Library *DiskfontBase;
 
 #define KBDBUFFER 10
 static unsigned char KbdBuffer[KBDBUFFER];
-unsigned char KbdBuffered;
+int KbdBuffered;
 
 #ifdef HACKFONT
 
@@ -609,10 +610,10 @@ amii_cleanup(void)
         Forbid();
         while (msg = (struct IntuiMessage *) GetMsg(HackPort))
             ReplyMsg((struct Message *) msg);
+        Permit();
         kill_nhwindows(1);
         DeleteMsgPort(HackPort);
         HackPort = NULL;
-        Permit();
     }
 
     /* Close the screen, under v37 or greater it is a pub screen and there may

sys/amiga/winext.h

@@ -63,7 +63,7 @@ extern struct Menu HackMenu[];
 extern struct Menu *MenuStrip;
 extern struct NewMenu GTHackMenu[];
 extern APTR *VisualInfo;
-extern unsigned char KbdBuffered;
+extern int KbdBuffered;
 extern struct TextFont *TextsFont;
 extern struct TextFont *HackFont;
 extern struct IOStdReq ConsoleIO;